1. Field of the Invention
The present invention relates to optical driving units used in optical apparatuses, such as TV cameras and video cameras.
2. Description of the Related Art
Conventionally, changes in servo-driving and manual driving for zoom operation used to be carried out by manually operating a mechanical clutch switching mechanism, but recently, both servo-driving and manual driving have come to be possible without necessitating this manual clutch switching (see Japanese Patent Laid-Open No. 1999-287944).
Furthermore, several methods have been adopted for TV and video image-taking. There is the image-taking method of changing the zoom position while imaging an object at a certain zoom position and then returning to the original zoom position and continuing the imaging, and there is also the image-taking method using presetting functions, as disclosed in Japanese Patent Laid-Open Nos. 2001-124977, 2001-124978 and 2001-124979. In these image-taking methods, a desired zoom position or speed is stored beforehand as preset information, and by turning on a preset switch during the image-taking, the zoom lens optical system is moved to that zoom position, or the zoom lens optical system is moved at the stored speed.
To perform this kind of image-taking method, a lens driving unit (also referred to as a xe2x80x9cdrive unitxe2x80x9d) is provided with a button-type switch, and the drive unit has a zoom operation function that is configured such that when this switch is operated, the zoom lens is moved in the direction towards the tele end (or the wide end), and when the switch is released, the zoom lens is returned to the original zoom position.
Furthermore, another image-taking method is one in which the camera operator sets the desired zoom position. That is to say, the lens driving unit is provided with a volume dial for setting the zoom position (over the entire range from telephoto end to wide-angle end) to which the camera operator wants to move the zoom, and the movement target of the zoom is set by operating this volume dial.
Then, when a button-type switch is operated, the zoom lens is servo-driven to the zoom position set with the volume dial, and when that switch is released, it returns to the original zoom position. In the following, this is referred to as xe2x80x9cpreset zoom reciprocating function.xe2x80x9d
Furthermore, there is also the method of storing a zoom position to be set in a storage circuit within the lens driving unit by operating a button-type operating member (switch).
Moreover, there are driving units provided with a plurality of button-type operating members (switches), that have a zoom operating function (preset function), with which, by operating the button-type operating members, a zoom position can be stored, the zoom can be moved into the direction of the zoom position, and stopped when it has reached the stored position. That is to say, the camera operator moves the zoom into the position preset beforehand, and by turning a MEMO (memory) switch on, the zoom position at that time is stored as the preset position. In the preset operation, the zoom is moved by motor-driven mechanism to the zoom position when turning a start switch on. The zoom driving speed at that time is a preset speed stored by a method similar to the setting position of a zoom speed setting volume, maximum speed, or the speed preset function described below.
With another speed preset function, in order to set a preset speed, the camera operator adjusts the operation amount of a zoom control switch such that it is set beforehand to the desired speed, the zoom is moved, and, by turning on a MEMO switch during the movement, the zoom speed and movement direction at that time are stored as the preset speed. In the preset operation, the zoom is then moved by motor-driven mechanism to the zoom end with the stored preset speed and direction by turning on a speed switch.
Thus, there are lens systems with which it is possible to servo-drive or manually drive the zoom without necessitating mechanical clutch switching, and that are provided with such zoom functions as a preset zoom reciprocating function.
In cameras equipped with an auto-focusing function (which is a function not used for the zoom portion), due to the auto-focusing characteristics, it is sometimes not possible to pursue the object with the auto-focus when imaging fast-moving objects or objects that are not well suited for auto-focusing. For this reason, when pursuing fast-moving objects or when trying to focus objects that are difficult to focus, it is preferable to switch to manual focusing and continue with the image-taking. There are examples of systems having a function with which this change between auto-focus and manual focus is not performed by a switch or the like, but instead the auto-focusing is immediately canceled when a manual focusing operation is detected, and priority is given to the manual focusing operation (see for example Japanese Patent Laid-Open No. 1993-14793).
However, if a lens system, in which instantaneous changing between servo-driving and manual driving of the zoom is possible without mechanical clutch switching, is equipped with the above-described preset zoom reciprocating function, preset function or speed preset function, then the camera operator may operate the zoom manually while the preset zoom reciprocating function is carried out. For example, when the object to be imaged is a bird or other animal, one often captures that image while gradually zooming in from a wide field angle with a constant slow (low-speed) zoom, until the animal fills out the image-taking area. In this case, the various preset zoom functions explained in above-described examples are all very useful. However, there is no guarantee that the animal and the bird will stay still in one place, and it will often move in the midst of zooming in. In that case, it is necessary to pursue the object.
In order to pursue the object in such a case even though the preset zoom function (or preset zoom reciprocating function, preset function, speed preset function) is currently being carried out, that function needs to be cancelled, and the camera operator needs to operate the zoom intentionally to decide the frame by his own intent. In this case, it is not desirable that at the moment when the camera operator has finished manual driving or thereafter, the zoom moves due to a continuation of the preset zoom function.
It is thus an object of the present invention to provide an optical apparatus that can be servo-driven and manually driven without switching a mechanical clutch and that is provided with a preset zoom function for driving an optical adjustment member by servo-driving using a stored position or a stored speed, wherein it can be prevented that the optical adjustment member is moved against the camera operator""s intent after a manual operation while that function is being carried out.
In order to attain this object, a first optical driving unit according to the present invention includes a driving mechanism that allows servo-driving and manual driving of an optical adjustment member, the driving mechanism allowing manual driving of the optical adjustment member during servo-driving without necessitating a switching operation; a storage circuit that stores at least one driving position of the optical adjustment member; and a control circuit that performs preset driving control through which the optical adjustment member is servo-driven to the driving position stored in the storage circuit. The control circuit aborts the preset driving control if manual driving of the optical adjustment member is detected during the preset driving control.
In order to attain the above-stated object, a second optical driving unit according to the present invention includes a driving mechanism that allows servo-driving and manual driving of the optical adjustment member, the driving mechanism allowing manual driving of the optical adjustment member during servo-driving without necessitating a switching operation; a storage circuit that stores a driving speed of the optical adjustment member; and a control circuit that performs preset driving control through which the optical adjustment member is servo-driven at the driving speed stored in the storage circuit. The control circuit aborts the preset driving control if manual driving of the optical adjustment member is detected during the preset driving control.